01 - Heat the milk in a small saucepan until steaming without boiling. Add Earl Grey tea bags and 2 tsp lavender; steep for 15 minutes. Remove tea bags, strain out lavender, and let cool completely. Reserve 2–3 tbsp for frosting; use remainder for cake batter.
02 - Preheat oven to 350°F. Grease and line two 8-inch round cake pans. Whisk together flour, baking powder, baking soda, and salt. In a large bowl, cream butter and sugar until light and fluffy. Beat in eggs one at a time, then add vanilla. Alternately add flour mixture and infused milk, beginning and ending with flour, mixing just until combined. Divide batter evenly between pans. Bake 25–30 minutes until a toothpick comes out clean. Cool 10 minutes in pans, then transfer to rack to cool completely.
03 - Combine water, sugar, and lavender in a small saucepan. Bring to a simmer, stirring until sugar dissolves. Remove from heat; steep 10 minutes, strain, and cool completely.
04 - Beat butter on medium-high speed until creamy. Gradually add powdered sugar, then vanilla and salt. Beat in reserved infused milk, 1 tbsp at a time, until desired consistency is reached.
05 - Brush cooled cake layers with lavender syrup. Place one cake layer on serving plate, spread with frosting. Top with second layer, frost top and sides. Garnish with additional dried lavender if desired.